Explore the vast range of titles available.

Spectrometers with ever-smaller footprints are sought after for a wide range of applications in which minimized size and weight are paramount, including emerging in situ characterization techniques. We report on an ultracompact microspectrometer design based on a single compositionally engineered nanowire. This platform is independent of the complex optical components or cavities that tend to constrain further miniaturization of current systems. We show that incident spectra can be computationally reconstructed from the different spectral response functions and measured photocurrents along the length of the nanowire. Our devices are capable of accurate, visible-range monochromatic and broadband light reconstruction, as well as spectral imaging from centimeter-scale focal planes down to lensless, single-cell–scale in situ mapping.

High-performance glazing technologies are essential for achieving the occupant comfort and building energy efficiency required in contemporary and future buildings. In real-world applications, glazing façades are selected from a steadily increasing number of glazing technologies. However, the authors could not identify a systematic and comprehensive review and classification of glazing technologies in the literature. This creates a barrier when comparing typologically different glazing technologies and combining multiple technologies in a glazing unit. This paper provides a systematic review and classification of established and emerging glazing technologies based on publications from 2001–2022 which were interpreted following the PRISMA methodology. This study reveals that the majority of high-performance glazing systems used in practice are in multi-layer glazing configurations and that the glazing system performance can focus on including additional and multiple functionalities, which aim at improving overall building performance. It was also found that there is a large potential for improvement of multilayer, evacuated, aerogels, electrochromic, and solar cell glazing by incorporating other technologies or innovative materials in multi-layer glazing units for either improving existing technologies or for the development of new ones. However, their longevity, robustness, and cost affordability should be ensured.

Existing buildings with large glazing ratios within subtropical Mediterranean climates face substantial challenges for thermal and visual control of their indoor environment. Previous research by the same authors has already identified the potential of incorporating both solar–PDLC (polymer-dispersed liquid crystal) and SPD (suspended particle device) switchable films within facades exposed to high solar insolation to provide a wide dynamic range of visual transparencies. This paper identifies a novel application for switchable laminates within a dynamic external shading device that permits the casting of a shadow on demand onto existing fenestration. This study compares the degree of glare within an enclosed space attained by a conventional opaque overhang over a window to that achieved with glass shading overhangs incorporating two types of switchable films. Using a scale model in a field test setting, indoor illumination and glare measurements are investigated under different states of switchable films and compared to those provided by conventional static glazing, with and without ordinary external overhangs under identical field test conditions. Results show that switchable overhangs in their transparent/bleached state can allow the ingress of daylight without creating excessive glare, whereas in their translucent/tinted state, switchable shades can deliver a level of glare protection similar to that provided by an opaque shading overhang.

As human skin is an important barrier and thermal regulator of the human body, the building \"skin\" is the first critical element in defining goals for building energy efficiency and Indoor Environmental Quality (IEQ). The glazing part of a building envelope is particularly critical because it is the most vulnerable envelope element to heat gain and heat loss accounting for around 50% of the building's energy consumption. Increasingly stringent regulations imposed over time mandate the adoption of high-performance facades. In this regard, in the second half of the twentieth century, Double Skin Facades (DSF) were developed. However, with cavity widths varying from 50 cm (1.64 ft) up to 2 m (6.56 ft), DSFs are rather space-consuming and require high installation and maintenance costs. For this purpose, a Closed Cavity Facade (CCF) was developed as a specific DSF system. In its simplest form, a CCF consists of a double or triple glazing unit (DGU or TGU) on the inner layer and single glazing on the outer one, forming a sealed non-ventilated cavity (about 20 cm width) with automated blinds in between which, given its dynamic behaviour, can contribute to balance the demand for energy saving and enhancement of IEQ. This study, using Energy Plus and IDA ICE building performance simulation tools, investigates the performance of several CCF configurations and geometries, for the eight climate zones of the USA, and compares them to the baseline (a DGU). MATELab, an office-like test facility at the University of Cambridge was used as the model for the simulations, which was beforehand experimentally validated. The CCF configurations investigated, led to a decrease of energy consumption in the range of 19-44% compared to the conventional DGU used as the baseline. This is mainly attributed to the improved thermal transmittance and solar heat gain coefficient (SHGC) because of integrating Venetian blinds in the cavity. A higher performance improvement is observed in cooling-dominated locations since CCF reduces solar gain through the facade, which is the main contributor to energy consumption. Furthermore, it was shown that suitable selection of the components of a CCF system (such as the colour of blinds and the type of coatings) results in an additional 1-2% improvement of its thermal performance, cutting down overheating phenomena, retaining the glass cavity temperatures below the critical value, and reducing the radiant discomfort providing extra benefits in terms of IEQ and occupant's productivity.

As human skin is an important barrier and thermal regulator of the human body, the building \"skin\" is the first critical element in defining goals for building energy efficiency and Indoor Environmental Quality (IEQ). The glazing part of a building envelope is particularly critical because it is the most vulnerable envelope element to heat gain and heat loss accounting for around 50% of the building's energy consumption. Increasingly stringent regulations imposed over time mandate the adoption of high-performance façades. In this regard, in the second half of the twentieth century, Double Skin Façades (DSF) were developed. However, with cavity widths varying from 50 cm (1.64 ft) up to 2 m (6.56 ft), DSFs are rather space-consuming and require high installation and maintenance costs. For this purpose, a Closed Cavity Façade (CCF) was developed as a specific DSF system. In its simplest form, a CCF consists of a double or triple glazing unit (DGU or TGU) on the inner layer and single glazing on the outer one, forming a sealed non-ventilated cavity (about 20 cm width) with automated blinds in between which, given its dynamic behaviour, can contribute to balance the demand for energy saving and enhancement of IEQ. This study, using Energy Plus and IDA ICE building performance simulation tools, investigates the performance of several CCF configurations and geometries, for the eight climate zones of the USA, and compares them to the baseline (a DGU). MATELab, an office-like test facility at the University of Cambridge was used as the model for the simulations, which was beforehand experimentally validated. The CCF configurations investigated, led to a decrease of energy consumption in the range of 19-44% compared to the conventional DGU used as the baseline. This is mainly attributed to the improved thermal transmittance and solar heat gain coefficient (SHGC) because of integrating Venetian blinds in the cavity. A higher performance improvement is observed in cooling-dominated locations since CCF reduces solar gain through the façade, which is the main contributor to energy consumption. Furthermore, it was shown that suitable selection of the components of a CCF system (such as the colour of blinds and the type of coatings) results in an additional 1-2% improvement of its thermal performance, cutting down overheating phenomena, retaining the glass cavity temperatures below the critical value, and reducing the radiant discomfort providing extra benefits in terms of IEQ and occupant's productivity.

Switchable glazing has made great strides to increase its potential of being deployed in adaptive building facades. These can provide shading solutions in climates with high solar insolation without compromising outlook and views, while allowing for privacy on demand. This paper further builds on previous knowledge and investigates the potential of a novel switchable assembly, comprising a dual dynamic solar-PDLC (Polymer Dispersed Liquid Crystal) and SPD (Suspended Particle Device) films, deployed in a side-lit, scale model setup for field testing. Using a comparative approach with static glazing, luminance photometry is used to determine the Daylight Glare Probability (DGP) provided by the different states of the switchable glazing. The measurements obtained assess the ability of this novel assembly of switchable films, to provide for privacy and glare control through the conversion of windows into opaque elements.

In the last few decades, the energy consumption of individual buildings has been steadily improving. As a result, research efforts are shifting towards acquiring a deeper understanding of occupant comfort, health, and well-being in the built environment. However, existing techniques used to measure and predict the comfort of occupants have seen little change since Fanger. New research attempts are hence focusing on methods to gather more data, more frequently, and less intrusively. A little explored source of data is the one gathered from real-time videos of occupants, the so-called facial action units (FAU), which is the focus of this paper. These are the facial movements and positions that constitute the basic elements of emotions. Using software developed in the realm of affective computing, seven building occupants were monitored for a period of 2 weeks, whilst also completing surveys that gathered information about the office environment, and their work and personal life. Results found that participants that were happy with their office space showed significantly higher average values of the Cheek Raiser (AU06) and Lid Tightener (AU07) facial action units. These findings show the potential of using FAUs to assist in the control and design of buildings in a human-centric manner.

The design trend of most commercial and office buildings over the past three decades focused on attaining a façade design with the highest possible window to wall ratio. Whereas this approach appears to satisfy the aesthetic scope of developing buildings that look ‘modern and transparent’ to maximise on real estate value, the demand for heating and cooling of these buildings tends to fall short of what one should expect. Literature review shows the possible benefits of switchable glass. This paper proposes a methodology for a novel switchable glazing assembly identified as having the potential of offering increased occupant comfort, particularly in providing sufficient daylight and glare control without diminishing the view quality. The hypothesis is that switchable glazing may have a substantial potential to achieve lower cooling loads and improved indoor visual comfort without compromising views and a positive outlook.

A design methodology is advanced primarily to determine the tensile strength of annealed and tempered glass. The proposed approach consists of an analytical method to assess the tensile strength of glass, sf, and a computer algorithm which is used to compute the applied equivalent uniform stress, sp. The glass design approach put forward endeavours to ensure that the surface tensile strength of glass is not exceeded by the equivalent uniform stress. The analytical method, referred to as the General Crack Growth Model, is related to the fundamental properties of the glass surface and incorporates all factors that are known to significantly affect the strength of glass. The General Crack Growth Model is based on the comparison of recent fracture mechanics methods and empirical formulations proposed elsewhere. The proposed glass strength equation or the derived glass strength charts may be used to determine the maximum allowable surface tension, sf. The performance of the proposed General Crack Growth Model is initially verified by ring-on-ring testing of annealed and tempered glass. The existing and proposed glass failure models rely on the summation of the stresses present on the glass surface to determine the structural suitability of the glass element. This makes these accurate models unattractive for everyday design. A computer algorithm, called Glasstress, has therefore developed to automatically summate the surface stresses and determine the equivalent uniform stress sp, from the results of finite element analyses. The proposed glass design approach and finite analyses are used to optimise typical bolted connections in glass and to propose an alternative, stronger adhesive connection. These strength predictions are verified by experimental investigation. Finally, the glass design approach is also verified by comparing the failure predictions made for laterally loaded glass plates to results obtained from independent test data.